452 



Tables of Weights and Measures, 



[June, 



Article VII. 



Talks of Weights and Measures, 



The diversity in the weiglits aDd measures of different nations 

 occasions considerable trouble to the readers of foreign books of 

 science, and sometimes even prevents them from fully compre- 

 hending their authors. On that account we think it will be at- 

 tended with considerable convenience to our readers if we insert 

 in this place tables of the most common weights and measures 

 that occur in foreign books. As this journal may likewise fall 

 into the hands of foreigners, we shall for their convenience in- 

 sert also tables of the weights and measures used in England. 



I. English Weights and Measures, 



There are two kinds of weights used in England ; namely, 

 Troy weight and Avoirdupois weight. The smallest weight in 

 both is the grain, which v^as conceived when first brought into 

 use, to be equivalent to the weight of a grain of ripe barley well 

 dried. The Avoirdupois weight is the one in common use, and 

 is employed to weigh all heavy articles. Hence it does not 

 usually descend so low as the grain. Troy weight (so called, 

 according to Dr. Smith, because employed at a great annual 

 fair at Troys, a town in France) is used for weighing gold and 

 silver, apothecaries' goods, and some other articles. It is the 

 weight always employed in English chemical books, except 

 when the contrary is expressly stated. 



1. Troy weight. 



24 grains make , . . 1 pennyvvcight, marked dvvt. 



20 pennyweights ....... i ounce, marked oz. 



12 ouoces 1 pound, marked lb. 



2. Avoirdupois weight, ' 



16 drams , 1 ounce. 



16 ounces. ............ 1 pound. 



28 pounds. 1 quarter, marked qrs. 



4 quarters .... ....... . i hundred weight, marked C.wt, 



20 hundredweight 1 ton, marked"^T. 



3. Troy weight, by Apothecaries, is divided as follows, and is 

 then known by the name of Apc^thecaries' weight. 



' 20 grains make , 1 scruple, marked 3. 



3 scruples 1 dram, marked 5. 



8 drams. 1 ounce, marked B» 



12 ounces 1 pound. 



